package com.v.im.imservice.util;

import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.ZooDefs;
import org.apache.zookeeper.ZooKeeper;
import org.apache.zookeeper.data.Stat;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.List;


public class ZkUtil {

    public static final Logger logger = LoggerFactory.getLogger(ZkUtil.class);

    private ZooKeeper zk = null;

    public ZkUtil(String url, int sessionTimeout) {
        try {
            zk = new ZooKeeper(url, sessionTimeout,null);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    /**
     * <p>创建zNode节点, String create(path<节点路径>, data[]<节点内容>, List(ACL访问控制列表), CreateMode<zNode创建类型>) </p><br/>
     * <pre>
     *     节点创建类型(CreateMode)
     *     1、PERSISTENT:持久化节点
     *     2、PERSISTENT_SEQUENTIAL:顺序自动编号持久化节点，这种节点会根据当前已存在的节点数自动加 1
     *     3、EPHEMERAL:临时节点客户端,session超时这类节点就会被自动删除
     *     4、EPHEMERAL_SEQUENTIAL:临时自动编号节点
     * </pre>
     * @param path zNode节点路径
     * @param data zNode数据内容
     * @return 创建成功返回true, 反之返回false.
     */
    public  boolean createPath( String path, String data ) {
        try {
            String zkPath =  zk.create(path, data.getBytes(), ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
            logger.info( "节点创建成功, Path: " + zkPath + ", content: " + data );
            return true;
        } catch ( KeeperException e ) {
            logger.error( "节点创建失败, 发生KeeperException! path: " + path + ", data:" + data
                    + ", errMsg:" + e.getMessage(), e );
        } catch ( InterruptedException e ) {
            logger.error( "节点创建失败, 发生 InterruptedException! path: " + path + ", data:" + data
                    + ", errMsg:" + e.getMessage(), e );
        }
        return false;
    }

    /**
     * <p>删除一个zMode节点, void delete(path<节点路径>, stat<数据版本号>)</p><br/>
     * <pre>
     *     说明
     *     1、版本号不一致,无法进行数据删除操作.
     *     2、如果版本号与znode的版本号不一致,将无法删除,是一种乐观加锁机制;如果将版本号设置为-1,不会去检测版本,直接删除.
     * </pre>
     * @param path zNode节点路径
     * @return 删除成功返回true,反之返回false.
     */
    public boolean deletePath( String path ){
        try {
            zk.delete(path,-1);
            logger.info( "节点删除成功, Path: " + path);
            return true;
        } catch ( KeeperException e ) {
            logger.error( "节点删除失败, 发生KeeperException! path: " + path
                    + ", errMsg:" + e.getMessage(), e );
        } catch ( InterruptedException e ) {
            logger.error( "节点删除失败, 发生 InterruptedException! path: " + path
                    + ", errMsg:" + e.getMessage(), e );
        }
        return false;
    }

    /**
     * <p>更新指定节点数据内容, Stat setData(path<节点路径>, data[]<节点内容>, stat<数据版本号>)</p>
     * <pre>
     *     设置某个znode上的数据时如果为-1，跳过版本检查
     * </pre>
     * @param path zNode节点路径
     * @param data zNode数据内容
     * @return 更新成功返回true,返回返回false
     */
    public boolean writeData( String path, String data){
        try {
            Stat stat = zk.setData(path, data.getBytes(), -1);
            logger.info( "更新数据成功, path：" + path + ", stat: " + stat );
            return true;
        } catch (KeeperException e) {
            logger.error( "更新数据失败, 发生KeeperException! path: " + path + ", data:" + data
                    + ", errMsg:" + e.getMessage(), e );
        } catch (InterruptedException e) {
            logger.error( "更新数据失败, 发生InterruptedException! path: " + path + ", data:" + data
                    + ", errMsg:" + e.getMessage(), e );
        }
        return false;
    }

    /**
     * <p>读取指定节点数据内容,byte[] getData(path<节点路径>, watcher<监视器>, stat<数据版本号>)</p>
     * @param path zNode节点路径
     * @return 节点存储的值,有值返回,无值返回null
     */
    public String readData( String path ){
        String data = null;
        try {
            data = new String( zk.getData( path, false, null ) );
            logger.info( "读取数据成功, path:" + path + ", content:" + data);
        } catch (KeeperException e) {
            logger.error( "读取数据失败,发生KeeperException! path: " + path
                    + ", errMsg:" + e.getMessage(), e );
        } catch (InterruptedException e) {
            logger.error( "读取数据失败,发生InterruptedException! path: " + path
                    + ", errMsg:" + e.getMessage(), e );
        }
        return  data;
    }

    /**
     * <p>获取某个节点下的所有子节点,List getChildren(path<节点路径>, watcher<监视器>)该方法有多个重载</p>
     * @param path zNode节点路径
     * @return 子节点路径集合 说明,这里返回的值为节点名
     * <pre>
     *     eg.
     *     /node
     *     /node/child1
     *     /node/child2
     *     getChild( "node" )户的集合中的值为["child1","child2"]
     * </pre>
     *
     *
     *
     * @throws KeeperException
     * @throws InterruptedException
     */
    public List<String> getChild(String path ){
        try{
            List<String> list=zk.getChildren( path, false );
            if(list.isEmpty()){
                logger.info( "中没有节点" + path );
            }
            return list;
        }catch (KeeperException e) {
            logger.error( "读取子节点数据失败,发生KeeperException! path: " + path
                    + ", errMsg:" + e.getMessage(), e );
        } catch (InterruptedException e) {
            logger.error( "读取子节点数据失败,发生InterruptedException! path: " + path
                    + ", errMsg:" + e.getMessage(), e );
        }
        return null;
    }

    /**
     * <p>判断某个zNode节点是否存在, Stat exists(path<节点路径>, watch<并设置是否监控这个目录节点，这里的 watcher 是在创建 ZooKeeper 实例时指定的 watcher>)</p>
     * @param path zNode节点路径
     * @return 存在返回true,反之返回false
     */
    public boolean isExists( String path ){
        try {
            Stat stat = zk.exists( path, false );
            return null != stat;
        } catch (KeeperException e) {
            logger.error( "读取数据失败,发生KeeperException! path: " + path
                    + ", errMsg:" + e.getMessage(), e );
        } catch (InterruptedException e) {
            logger.error( "读取数据失败,发生InterruptedException! path: " + path
                    + ", errMsg:" + e.getMessage(), e );
        }
        return false;
    }

    /**
     * 关闭ZK连接
     */
    public void releaseConnection() {
        if ( null != zk ) {
            try {
                zk.close();
            } catch ( InterruptedException e ) {
                logger.error("release connection error ," + e.getMessage() ,e);
            }
        }
    }

}
